Several recent reports have documented the presence of antibiotics in drinking water
sources, the result of incomplete treatment of waste streams originating from municipal
sources and livestock operations. Potassium permanganate (KMnO4) is
used by a number of utilities to address a range of issues (e.g., dissolved Mn, T&O), but little
is known about the effectiveness of KMnO4 for oxidizing antibiotics or the effect of treatment
on antibiotic potency of the treated water. This contribution reports for the first time on the
treatment of commonly detected antibiotics (trimethoprim, lincomysin, ciprofloxacin,
sulfamethoxazole, sulfamethizole, and chlortetracycline) with KMnO4. Kinetic studies
demonstrate that KMnO4 is a selective oxidant, exhibiting apparent second-order rate
constants with the target antibiotics at pH 7 ranging from <0.03 to 110 M-1 s-1. Reaction rates
are highly dependent on pH, and measured kinetic trends can be modeled by accounting for
changes in acid/base speciation of the target antibiotics. Kinetic model predictions also agree
closely with measurements of antibiotic treatment in drinking water utility source waters of
variable composition. Bioassay experiments show that oxidation products and intermediates
possess negligible antibacterial activity in comparison with the parent drugs. Includes 18 references, tables, figures.